Ancient Domains Of Mystery

In ADOM, you play an adventurer who has traveled to a remote mountain range to save Ancardia, the world of the game, from the forces of Chaos. You can either continue on with this quest or join on with Chaos, depending on the choices that you make in the game.
ADOM features a wide range of character races and classes, a point-based skill system, many subplots, and a detailed world that's inspired quite a few pieces of fan art and quite a bit of filking.